The connection fitting of this invention creates an improved sealing action by using a tubing with a special flattened double flanged end. The flattened double flange end seals with a O-ring seal retained in an annular recess in the end face of a mating male connector. The flattened double flanged end is formed by doubling over and flattening a portion of the tubing wall against a collar fitting or sleeve. This flattened double walled flange design has several advantages over flat single flanged fittings. The flattened double walled flange guard against failure and provide increased strength over a single walled flange. The flattened double flanged end accommodates conventional fittings and does not require any special connectors, fittings or tooling for use in existing applications. Improvements in conventional fittings often require special fittings and tooling.
The improved flattened double flanged end is produced using a machine press with a unique three press hit method. A sleeve is loosely positioned on the end of the tubing with a portion of the tubing wall protruding beyond the sleeve. The length of the extending wall is approximately equal to twice the intended flange height. The tube and sleeve are firmly secured within the machine press by a set of specially designed clamp dies. The clamp dies hold the tubing and sleeve in the proper position.
Using three separate press hits with three separate contact dies, the machine press expands the tubing wall against the face of the sleeve, flares an end portion of the tubing wall and presses the flaring into a flattened end flange. Each contact die has a center pilot and a contact face. The first contact die has an inwardly inclined conical contact face. On the first press hit, the press drives the pilot of the first contact die into the end of the tubing. The slightly larger diameter of the center pilot expands tubing walls against the sleeve's inner bore to secure the sleeve to the tube. In the last distance of travel of the stroke in the first press hit, the exposed tubing end contacts the inclined contact face of the contact die crimping the tubing wall outward into a shallow U-shaped flange bubble.
The second press hit uses a second contact die. The second contact die is comprised of a conical contact face with a greater incline angle relative to the center pilot than the first contact die. The hit stroke further flares the U-shaped flange in the tubing walls. The final press hit uses a third contact die with a flat contact face. The third press hit compacts the flared U-shape flange bubble and drives the tubing wall into a recess in the contact face to form the flattened double flange. The pilot of the second and third contact dies simply prevent the tubing walls from intruding into the conduit opening.
The use of this method to produce the flattened double flanged end is well suited for production application because the entire tooling process can be performed within a very short period of time. The impact method also eliminates any complicated machining or forming. The simplicity of the impact press also decreases the failure rate, while allowing for mass quantity production.
Accordingly, an object of this invention is to provide a novel and unique flanged connection fitting.
Another object of this invention is to provide a tubing with a flattened double flanged end for use as a connection fitting.
Another object of this invention is to provide a method of efficiently producing a tubing with a flattened double flanged end for use as a connection fitting.
Other objects will become obvious upon a reading of the following specification taken along with the drawings.